Hi, this is the notation for inclusion of all real
numbers.

We can also state numbers which are positive or negative with a sign on top of the R notation like so:
Answer:
- 43t - 22s - 3
Step-by-step explanation:
(–45t + 53s) + (–3 – 75s + 2t)
Opening the brackets
-45t + 53s -3 - 75s + 2t
Collecting like terms
-45t + 2t + 53s - 75s -3
Simplify the expression
-43t -22s - 3
-16 because you need to subtract -4 from -12
Your diagram doesn't clearly define what values correspond to what, can you explain.
$20,000
25,000,000 x 0.0002 = 5,000
5,000 x $4.00= $20,000